Experimental Determination of Frequency and Damping of a Printed Circuit Board Supported by Retainers

夾具支撐的印刷電路板之頻率和阻尼

陳本明(Beng-Ming Chen) ； Jahan Rasty

《中華民國振動與噪音工程學會論文集》 1996 (1996/04) Pp. 407-420

https://doi.org/10.30028/CSSVANNUAL.199604.0407

摘要

印刷電路板及其表面黏著零件通常因振動所產生的動態負荷過大而損壞，進而導致航太設備故障。爲提高產品可靠性，工程師對於產品受振動的反應需有深入瞭解。本實驗將印刷電路板以不同商用夾具支撐並量測其第一共振頻率及阻尼。
本研究以3( 上標f)階實驗進行自由振動測試，每一個案均取得兩組有效實驗值，而相同條件設定的個案也以電腦模擬計算其共振頻率。該資料則用來與實驗值比較，以確保實驗之正確性。至於系統阻尼則以對數遞減法求取，而支撐部份所引發之摩擦阻尼也加以計算。實驗數據經統計分析軟體處理，取得最接近之曲線方程式後，所得結果可供使用該夾具支撐印刷電路板者設計時參考。

關鍵字

共振頻率 ； 阻尼 ； 印刷電路板

並列摘要

Vibrations introduces excessive dynamic loading on printed circuit boards (PCB) and their surface mounted components, thus, causing premature failure of an electric/avionic equipment. In order to develop highly reliable products, an accurate understanding of the response of a product subject to vibration is required. This study was to determine the fundamental resonant frequency and damping of the PCB supported by different types of retainers.
Free vibration tests were conducted using a 3(superscript f) factorial experiment with two replications for each case. Computer simulations were also performed to estimate the fundamental resonant frequencies of the corresponding cases. The information was used for the guidance of the experiments and for the comparison with the real system response. The Logarithmic Decrement method was employed for the damping calculation. Frictional damping at the supports of the board/retainer system was determined as well. A statistical analysis software was utilized for curve fitting process. The results are summarized to provide the information when using retainers as PCB supports.

並列關鍵字

resonance ； damping ； printed circuit board